APA (7th ed.) Citation

ScienceDirect (Online service), Thorp, J. H., & Rogers, D. C. (2016). Keys to nearctic fauna (Fourth edition.). Elsevier Ltd..

Chicago Style (17th ed.) Citation

ScienceDirect (Online service), James H. Thorp, and D. Christopher Rogers. Keys to Nearctic Fauna. Fourth edition. Amsterdam: Elsevier Ltd., 2016.

MLA (9th ed.) Citation

ScienceDirect (Online service), et al. Keys to Nearctic Fauna. Fourth edition. Elsevier Ltd., 2016.